Parents looking to solve or prevent infant sleep problems face bewilderingly contradictory advice. On one hand, experts like Marc Weissbluth, professor of clinical pediatrics at Northwestern's Feinberg School of Medicine, recommend letting the child cry alone in his crib for as long as it takes to fall asleep. On the other, "attachment" theorists like Martha and William Sears say the most natural place for a young child to sleep is in her mother's arms.

Between the extremes, common recommendations from experts include these:

* Begin establishing consistent sleep routines by the time the baby is about 3 months old. It gets more difficult later.

* Avoid having the child fall asleep while nursing or taking a bottle. That sleep-milk association can be difficult to break.

* Institute a calm, regular bedtime routine, with quiet reading or singing instead of active games. Allow enough time so parent and child can relax.

* Encourage the child to attach to a "transitional object" such as a stuffed animal, favorite toy or special blanket to help cope with nighttime separation from parents.

* Once a child is big enough and old enough (talk with your pediatrician about the timing), stop feedings at nighttime awakenings.

* Help the child associate the crib with sleep and only sleep. Don't use the crib as a playpen, a place to restrain the child while an adult does housework or a place to punish the child.

You'll want to discuss persistent sleep problems with your pediatrician. Here are some organizations, Web sites and books that also offer practical advice and information:

* National Sleep Foundation, www.sleepfoundation.org.The Web site of this nonprofit group addresses numerous sleep issues for children and adults and includes the group's new childhood sleep guidelines.

* American Academy of Sleep Medicine (formerly the American Sleep Disorders Association), www.aasmnet.org, 708-492-0930. The Web site of this membership group of doctors and other professionals contains links to sleep resources and research, and also can direct patients to accredited sleep disorder centers (not all of which treat children).

* A Johnson & Johnson-owned parenting Web site, www.babycenter.com, offers plentiful age-specific sleep advice from a philosophically diverse array of pediatricians and psychologists who sometimes flatly contradict each other. Its sister site, www.parentcenter.com, addresses sleep questions for children aged 2 to 8.

* Kim West's Web site, www.sleeplady.com, includes information on infant sleep and her practice, which includes sleep plans tailored for babies and families. West also offers sleep workshops for new parents and some teleconferencing options for families who live outside the Washington and Baltimore areas. She can be reached by phone at 410-974-1600.

* Richard Ferber's "Solve Your Child's Sleep Problems" (Simon and Schuster, 1985), is probably the best-known book on infant sleep issues. Ferber, director of the Center for Pediatric Sleep Disorders at Children's Hospital in Boston, recommends letting children "cry it out," but encourages parents to check on the child frequently. The book also contains useful descriptions of children's sleep and wake cycles, and suggestions on how to structure nighttime from early infancy.

* "What To Expect the First Year" (Workman, 1989) and "What to Expect: The Toddler Years" (Workman, 1994), both by Arlene Eisenberg, Heidi E. Murkoff and Sandee E. Hathaway, address many early childhood sleep problems, drawing heavily on the Ferber philosophy.

* Jodi Mindell's "Sleeping Through the Night: How Infants, Toddlers and Their Parents Can Get a Good Night's Sleep" (HarperCollins, 1997) offers a variant of the "cry it out" theory. The author takes a somewhat gentler approach, particularly on comforting babies during night awakenings.

-- Joanne Kenen